Organic electroluminescent device

Abstract

An organic electroluminescent device includes a pair of electrodes; and an organic layer between the pair of electrodes, which includes a light-emitting layer, wherein the organic layer contains a compound represented by the following formula (I); and the light-emitting layer contains a iridium complex phosphorescent material: wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 each represents a hydrogen atom or a substituent, and contiguous substituents of R 1 to R 8 may be bonded to each other to form a condensed ring; R 9 represents an alkyl group, an alkenyl group, an aryl group, a hetero-aryl group, or a silyl group, and each of which group may be substituted with a substituent; and at least one of R 1 to R 9 represents a deuterium atom or a substituent containing a deuterium atom.

What is claimed is: 
     
       1. An organic electroluminescent device comprising:
 a pair of electrodes; and 
 an organic layer between the pair of electrodes, which comprises a light-emitting layer, 
 wherein the organic layer contains a compound represented by the following formula (I); and 
 the light-emitting layer contains an iridium complex phosphorescent material: 
 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7  and R 8  each represents a hydrogen atom or a substituent, and contiguous substituents of R 1  to R 8  may be bonded to each other to form a condensed ring; 
         R 9  represents an alkyl group, an alkenyl group, an aryl group, a hetero-aryl group, or a silyl group, and each of which group may be substituted with a substituent; and 
         at least one of R 1  to R 9  represents a deuterium atom or a substituent containing a deuterium atom, 
         wherein the iridium complex phosphorescent material contains a ligand bonding to an iridium atom via a carbene carbon. 
       
     
     
       2. The organic electroluminescent device of  claim 1 , wherein the iridium complex phosphorescent material containing a ligand bonding to an iridium atom via a carbene carbon is represented by the following formula (II): 
       
         
           
           
               
               
           
         
         wherein R 21 , R 22 , R 23 , R 25 , R 26 , R 27  and R 28  each represents a hydrogen atom or a substituent; 
         L 21  represents a ligand; 
         n 22  represents an integer of from to 1 to 3 
         n 21  represents an integer of from 0 to 4; and 
         C represents the carbene carbon coordinating to the iridium atom. 
       
     
     
       3. The organic electroluminescent device of  claim 2 , wherein the iridium complex phosphorescent material containing a ligand bonding to an iridium atom via a carbene carbon is represented by the following formula (III): 
       
         
           
           
               
               
           
         
         wherein R 31  represents an alkyl group or an aryl group; 
         R 35 , R 36  and R 37  each represents a hydrogen atom, a fluorine atom, an alkyl group, or a cyano group, and R 35  and R 36  or R 36  and R 37  may be bonded to each other to form a condensed ring structure; 
         L 31  represents a ligand; 
         n 32  represents an integer of from 1 to 3; 
         n 31  represents an integer of from 0 to 4; and 
         C represents the carbene carbon coordinating to the iridium atom. 
       
     
     
       4. An organic electroluminescent device comprising:
 a pair of electrodes; and 
 an organic layer between the pair of electrodes, which comprises a light-emitting layer, 
 wherein the organic layer contains a compound represented by the following formula (I); and 
 the light-emitting layer contains an iridium complex phosphorescent material: 
 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7  and R 8  each represents a hydrogen atom or a substituent, and contiguous substituents of R 1  to R 8  may be bonded to each other to form a condensed ring; 
         R 9  represents an alkyl group, an alkenyl group, an aryl group, a hetero-aryl group, or a silyl group, and each of which group may be substituted with a substituent; and 
         at least one of R 1  to R 9  represents a deuterium atom or a substituent containing a deuterium atom, 
         wherein the iridium complex phosphorescent material contains a ligand bonding to an iridium atom via a nitrogen atom of a pyrazole structure. 
       
     
     
       5. The organic electroluminescent device of  claim 4 , wherein the iridium complex phosphorescent material containing a ligand bonding to an iridium atom via a nitrogen atom of a pyrazole structure is represented by the following formula (IV): 
       
         
           
           
               
               
           
         
         wherein R 41 , R 42 , R 43 , R 45 , R 46 , R 47  and R 48  each represents a hydrogen atom or a substituent; 
         L 41  represents a ligand; 
         n 42  represents an integer of from 1 to 3; and 
         n 41  represents an integer of from 0 to 4. 
       
     
     
       6. The organic electroluminescent device of  claim 5 , wherein the iridium complex phosphorescent material containing a ligand bonding to an iridium atom via a nitrogen atom of a pyrazole structure is represented by the following formula (V): 
       
         
           
           
               
               
           
         
         wherein R 52  and R 53  each represents a hydrogen atom, an alkyl group, or an aryl group; 
         R 55 , R 56  and R 57  each represents a hydrogen atom, a fluorine atom, an alkyl group, or a cyano group, and R 55  and R 56  or R 56  and R 57  may be bonded to each other to form a condensed ring structure; 
         L 51  represents a ligand; 
         n 52  represents an integer of from 1 to 3; and 
         n 51  represents an integer of from 0 to 4. 
       
     
     
       7. An organic electroluminescent device comprising:
 a pair of electrodes; and 
 an organic layer between the pair of electrodes, which comprises a light-emitting layer, 
 wherein the organic layer contains a compound represented by the following formula (I), and 
 the light-emitting layer contains an iridium complex phosphorescent material which contains a ligand bonding to an iridium atom via the nitrogen atom of a pyridine structure and is represented by the formula (VI): 
 
       
         
           
           
               
               
           
         
         wherein R′, R 3 , R 4 , R 5 , R 6 , and R 8  each represents a hydrogen atom or a substituent, and contiguous substituents of R 1 , R 3  to R 6 , and R 8  may be bonded to each other to form a condensed ring; 
         R 2  and R 7  each independently represents a hydrogen atom, a deuterium atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a hetero-aryl group, an amino group, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, a ureido group, a phosphoric acid amido group, a hydroxyl group, a mercapto group, a halogen group, a cyano group, a sulfo group, a carboxyl group, a nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group, a silyl group, a silyloxy group, wherein these substituents may further be substituted with other substituents, and these substituents may be bonded to each other to form a ring; 
         R 9  represents an alkyl group, an alkenyl group, an aryl group, a hetero-aryl group, or a silyl group, and each of which group may be substituted with a substituent; and 
         at least one of R 1  to R 9  represents a deuterium atom or a substituent containing a deuterium atom, 
       
       
         
           
           
               
               
           
         
         wherein R 61 , R 62 , R 63 , R 64 , R 65 , R 66 , R 67 , and R 68  each independently represents a hydrogen atom or a substituent; 
         L 61  represents a ligand, wherein the ligand is 
       
       
         
           
           
               
               
           
         
         n 62  represents an integer of 2; and 
         n 61  represents an integer of 1. 
       
     
     
       8. The organic electroluminescent device of  claim 7 , wherein the iridium complex phosphorescent material has a maximum emission wavelength of smaller than 470 nm. 
     
     
       9. The organic electroluminescent device according to  claim 7 , wherein the compound represented by formula (I) is represented by the formula (VIII): 
       
         
           
           
               
               
           
         
         wherein R 81 , R 83 , R 84 , R 85 , R 86 , and R 88  each represents a hydrogen atom or a substituent, and contiguous substituents of R 81 , R 83  to R 86 , and R 88  may be bonded to each other to form a condensed ring structure 
         R 82  and R 87  each independently represents a hydrogen atom, a deuterium atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a hetero-aryl group, an amino group, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfonyl group, a sulfinyl group, a ureido group, a phosphoric acid amido group, a hydroxyl group, a mercapto group, a halogen group, a cyano group, a sulfo group, a carboxyl group, a nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group, a silyl group, a silyloxy group, wherein these substituents may further be substituted with other substituents, and these substituents may be bonded to each other to form a ring; 
         A represents a linking group; 
         n 81  represents an integer of from 2 to 6; and 
         the compound represented by the formula (VIII) contains at least one deuterium atom. 
       
     
     
       10. The organic electroluminescent device of  claim 7 , wherein the compound represented by the formula (I) is contained in the light-emitting layer.